Socioeconomic benefits of large carnivore restoration in the Eastern United States
The decline of large carnivores has released populations of large herbivores in areas throughout the world, causing increased animal-vehicle collisions and damage to agriculture and biodiversity. In the United States, vehicle collisions with white-tailed deer (Odocoileus virginianus) cause $1.1 billion in damage, 29,000 injuries, and 211 deaths each year. Attempts to control overabundant deer have largely failed, and deer-vehicle collision (DVC) rates continue to rise. Could recolonization of the eastern US by cougars (Puma concolor) reduce deer densities, DVCs, and the resulting costs to human society? Here, we present the first valuation of an ecosystem service that could be provided by the restoration of a large carnivore to its former range. We developed deer population projection models based on cause-specific mortality rates compiled from 3,952 radio-collared deer, and we coupled these projections with socioeconomic valuations.
Our models showed that cougars would likely reduce deer densities and DVCs by 22% within 50 years of successful establishment, resulting in 53,000 prevented human injuries, 384 prevented human fatalities, and $4.41 billion in avoided costs. Analysis of data from South Dakota, a state recently recolonized by cougars, supported model projections and showed that cougars currently save residents $1.4 million annually in avoided collision costs. Thus, recolonizing cougars would likely provide a valuable ecosystem service in the eastern US through a coupled ecological-anthropogenic cascade. Large carnivore restoration may have substantial positive effects on human society by reducing overabundant ungulate populations, in addition to the biodiversity increases typically discussed by ecologists.